The present invention relates, in general, to electronics, and more particularly, to methods of forming semiconductor regulators and structures.
In the past, the electronics industry utilized various techniques for implementing voltage regulator systems. One particular type often referred to as continuous time mode or linear regulators have wide application. Typically, a linear voltage regulator included a linear amplifier that sensed the output voltage and compared it to a desired voltage reference. If the output voltage was less than the reference voltage, the linear amplifier enabled a output transistor to increase the voltage applied to the output. One particular problem occurred when restarting from a power down or standby mode. A capacitor typically was connected in parallel with the load. During the power down or stand-by mode, the capacitor discharged. Upon applying power, the linear amplifier sensed the low voltage and drove the output transistor to quickly charge the load capacitor. The resulting load current during this start-up period generally was much greater than the desired operating load current value. For many applications, such as battery powered operations, the large load current resulted in damaging the battery and shortening the useful battery lifetime.
Accordingly, it is desirable to have a voltage regulator that limits load current during the start-up mode, that does not damage the battery during the start-up mode, and that does not reduce the battery""s useful lifetime.